In the above letter, I love the idea of the border above. It gives the overall letter a nice touch, and it make it look very professional. I also like the fact that it gives the letter a little color, without providing too much. I also like how all the text in the letter is aligned to the left, also making it look professional. Overall this is definitely my favorite example of all 3.
One thing I like about this letter is that it is very simple and it used numbers to provide important points and purposes of the letter. However, I do not like that it does not have a letterhead. Without a letterhead, I believe that a letter does not look professional. I also think that this letter looks very boring, and long.
With the letter above, I like that everything once again is aligned to the left. I also really like that this letter has a letterhead, which directly points out what the letter is about. To whoever receives this letter, they are able to conclude what the letter is going to be about just by quickly glancing at it.
My letter: